One must remember most of these "respondents" are at home in the daytime, using a landline rather than a cellular phone, and have the free time to answer a pollster's questions.
Hardly a good sample of your average American in 2008.
Actually, I have my suspicions about polls in USA 2008. I think they've finally tossed up their hands and are just making them up. It's cheaper and more profitable that way. And who's to blow the whistle on 'em?
Even when home, it is extremely rare for me to talk to ANY sales/poll/political caller. I’m generally off the phone before they can get the first sentence out of their mouths.